How? Of course asking OP to add features for a site he offers for free is wrong, but I don't think he's wrong about gif. As far as I know all the "gif" sharing sites like giphy and stickers in chat apps like discord, etc actually use webms/webps.
Twitter for instance automatically converts gif to h264.
However there is a point to be made that iOS only grants VP9 decoding to Youtube, certain colourspaces fail to decode on Android etc. ergo gif is a safe default.